Y8 Energy Flashcards
What is the law of conservation of energy?
The law that states that energy cannot be created or destroyed only transferred.
What are light, sound and electricity examples of?
Ways to transfer energy between stores.
What does the thermometer measure and in what unit?
It measures heat in degrees celsius (°C)
What does temperature measure?
Average thermal energy.
What is thermal energy?
The total energy in heat.
What has more thermal energy a warm bath or a kettle.
The bath. Although a kettle has more heat, as the bath needs more heat to be transferred to be as hot as the kettle due to its volume it is spread out evenly through the liquid until it reaches an equilibrium.
What happens when you heat particles?
They gain kinetic energy and vibrate or more faster.
Why can the amount of energy needed to heat something vary?
Due to different masses, material (conductivity) and how much it needs to rise.
What is an equilibrium?
When an object has the same thermal energy throughout the entire object.
What is a renewable fuel?
A fuel that will never run out. It only produces greenhouse gases when built, not whilst being used.
What are the different renewable fuels?
Wind, tidal, wave, hydroelectric, geothermal, biomass and solar power.
What is a non-renewable fuel?
A fuel that cannot be used sustanibly and will run out.
What are the different non-renewable fuels?
Fossil fuels: Crude oil, coal and natural gas.
Nuclear
How do fossil fuels provide energy?
- Fossil fuels burnt to heat water which turns to steam.
- Steam turns a turbine which spins a generator.
- The current is sent to different buildings through cables along the national grid
- The fossil fuels produce greenhouse gases, such as carbon dioxide.
What are the different ways thermal energy is transferred?
Conduction, convection or radiation.
What is conduction?
When particles vibrate due to being heated transferring heat through hitting other particles making them vibrate. It happens in solids.
What is convection?
- The part closest to the heat heats up moving faster causing them to move further apart and decreasing in density.
- As it it less dense than the colder particles, it rises
- The colder particles go to the bottom and heat up gaining speed causing them to move further apart and decreasing in density.
- The hotter particles rise to the top cool down and go back to the source of heat and the cycle repeats.
It occurs in gases and liquids.
What is power?
The rate of energy transfer - how much energy is transferred each second.
What are energy bills measured in?
kilowatts per hour (kWh)
How do you convert Watts into joules
Power (watts) X time (seconds)
How do you convert energy into power?
Energy (joules) divided by time (seconds)
What are some ways to reduce energy bills?
- Using fewer appliances or more efficient ones
- Insulated houses lose less thermal energy so less power would be neededto be used to heat up the house.